TTHM (Total Trihalomethanes) violations in Alaska
119 active public water systems in Alaska had a TTHM (Total Trihalomethanes) violation in the past three years, 23 of them in the latest quarter of EPA's data. What TTHM (Total Trihalomethanes) is and why it matters.
Health effects: Long-term exposure is associated with increased bladder cancer risk. Some studies link high TTHM exposure to adverse reproductive outcomes. Bromodichloromethane is classified as a possible human carcinogen.
Systems with a TTHM (Total Trihalomethanes) violation
Latest quarter first, then largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Eielson Air Force Base Eielson · Fairbanks North Star Borough County |
11,870 | 3 | 0 | |
|
Kotzebue Mun. Water System Kotzebue · Northwest Arctic Borough County |
3,234 | 2 | 0 | |
|
City of Hooper Bay Hooper Bay · County |
1,375 | 10 | 4 | |
|
Selawik Safewater Facility Selawik · Northwest Arctic Borough County |
846 | 9 | 3 | |
|
Emmonak Water System Emmonak · County |
820 | 10 | 3 | |
|
Kwethluk New Piped Water System Kwethluk · Bethel Census Area County |
760 | 11 | 2 | |
|
Ft. Yukon Public Water System Fort Yukon · Yukon-Koyukuk Census Area County |
665 | 6 | 1 | |
|
Scammon Bay Water System Scammon Bay · County |
637 | 7 | 0 | |
|
Buckland Water System Buckland · Northwest Arctic Borough County |
600 | 11 | 1 | |
|
Alakanuk Water System Alakanuk · County |
570 | 14 | 2 | |
|
Kiana Water System Kiana · Northwest Arctic Borough County |
455 | 7 | 2 | |
|
Angoon Public Water Angoon · County |
450 | 13 | 2 | |
|
Huslia Public Water System Huslia · Yukon-Koyukuk Census Area County |
323 | 4 | 2 | |
|
Conocophillips Willow Construction Camp Prudhoe Bay · North Slope Borough County |
300 | 1 | 0 | |
|
Ruby Water System Ruby · Yukon-Koyukuk Census Area County |
215 | 6 | 1 | |
|
Wales Water System Wales · Nome Census Area County |
173 | 9 | 2 | |
|
Allakaket Public Water System Allakaket · Yukon-Koyukuk Census Area County |
135 | 7 | 3 | |
|
Circle Washeteria Circle · Yukon-Koyukuk Census Area County |
110 | 6 | 0 | |
|
Tatitlek Water System Tatitlek · County |
95 | 8 | 0 | |
|
Rampart Washeteria Rampart · Yukon-Koyukuk Census Area County |
88 | 7 | 3 | |
|
Diomede Joint Utilities Little Diomede · Nome Census Area County |
83 | 11 | 1 | |
|
Gulkana Village Gulkana · County |
54 | 4 | 0 | |
|
Yksd Allakaket School Allakaket · Yukon-Koyukuk Census Area County |
52 | 6 | 0 | |
|
Doyon Utilities Jber Richardson Fort Richardson · Anchorage Municipality County |
20,284 | 1 | 0 | |
|
Unalaska Water System Unalaska · Aleutians West Census Area County |
9,400 | 6 | 0 | |
|
Soldotna Soldotna · Kenai Peninsula Borough County |
4,807 | 1 | 0 | |
|
Nome Joint Utility System Nome · Nome Census Area County |
3,920 | 1 | 0 | |
|
Haines Borough Haines · Haines Borough County |
2,376 | 6 | 0 | |
|
Bethel Heights Water System Bethel · Bethel Census Area County |
2,228 | 3 | 0 | |
|
Bethel-City S/d Water Bethel · Bethel Census Area County |
1,660 | 2 | 0 | |
|
Hilcorp Pboc Prudhoe Bay · North Slope Borough County |
1,200 | 2 | 0 | |
|
Hoonah PWS Hoonah · County |
980 | 7 | 0 | |
|
Chevak Water System Chevak · County |
938 | 7 | 2 | |
|
Mountain Village Water System Mountain Village · County |
887 | 11 | 2 | |
|
Sand Point Water System Sand Point · Aleutians East Borough County |
830 | 7 | 0 | |
|
Savoonga Water Supply Savoonga · Nome Census Area County |
802 | 5 | 2 | |
|
Noorvik Water System Noorvik · Northwest Arctic Borough County |
735 | 6 | 1 | |
|
Quinhagak Water System Quinhagak · Bethel Census Area County |
724 | 4 | 0 | |
|
Gambell Water System Gambell · Nome Census Area County |
669 | 10 | 2 | |
|
Kipnuk Water System Kipnuk · Bethel Census Area County |
639 | 8 | 0 | |
|
Kotlik Water System Kotlik · County |
617 | 9 | 1 | |
|
Pilot Station Water System Pilot Station · County |
580 | 6 | 1 | |
|
Shishmaref Water System Shishmaref · Nome Census Area County |
572 | 5 | 0 | |
|
St. Marys Water System Saint Mary's · County |
548 | 6 | 1 | |
|
Kongiganak Water System Kongiganak · Bethel Census Area County |
547 | 7 | 0 | |
|
Nunapitchuk Water System Nunapitchuk · Bethel Census Area County |
496 | 6 | 1 | |
|
Nenana Municipal Water Nenana · Yukon-Koyukuk Census Area County |
486 | 1 | 0 | |
|
Noatak Community Water System Noatak · Northwest Arctic Borough County |
485 | 6 | 1 | |
|
AC Alaska Commercial Store Bethel · Bethel Census Area County |
475 | 6 | 0 | |
|
Thorne Bay, City of Thorne Bay · County |
470 | 6 | 1 |
About this data
A system is counted once if any of its violations in the past three years involved TTHM (Total Trihalomethanes), including monitoring and reporting lapses. Rules violated and status in the table are for the whole system, not TTHM (Total Trihalomethanes) alone.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Alaska records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet.